During a hurricane, Mother Nature is a force to be reckoned with. The intense precipitation, flooding, and high winds strip materials from buildings, including siding, roof shingles, doors, and windows. These airborne debris are a major contributor to home damage and human injury. Therefore, when building on the coast, it’s imperative that your home is compliant with V-zone building codes. One building material to be very careful with is concrete.
Forceful waters and high velocity winds can cause concrete slabs to hydroplane, flip, or break into large chunks that could damage buildings and injure, even kill, people. As a result, building codes require such slabs be of frangible concrete. This means they are designed to break into smaller pieces which will sink rather than travel. So when constructing driveways, pool decks, and patios, it’s important your contractor follows these guidelines:
- No reinforcement should be used
- Slabs should not be thicker than four inches
- Slabs must remain structurally independent of the building
- Control joints must be spaced at 4-foot squares to encourage even breaking
When laying cement in V-zone areas, proper control joint spacing and depth are essential. According to the Portland Cement Association, placing control joints in the concrete surface at strategic locations creates weakened planes allowing the concrete to crack evenly. Spacing the control joints at 4-foot squares ensures the concrete will break into smaller pieces which will cause less damage during hurricanes.
Control joints may be tooled into the concrete surface at the time of placement or they may be sawed into the hardened concrete. Regardless, control joints should be cut to a depth of ¼ the slab thickness.
Not only is this control joint approach safer, it also produces a more aesthetically pleasing appearance since the crack forms below the finished concrete surface. This method can reduce the amount of hairline cracks on the surface of the cement.
So, when building your vacation home or remodeling to add a backyard oasis, make sure you only work with licensed contractors who are familiar with V-zone construction and the importance of cement control joints. If you’d like to learn more about concrete, check out our post about reducing surface cracking.
Blog by Jessica T. Smith for the Coastal Cottage Company